The word "walrus" is of Old Norse origin. It comes from the word "hrosshvalr" which literally means "horse whale". This is because the walrus's tusks resemble the teeth of a horse, and it is a marine mammal, similar to a whale.
Over time, "hrosshvalr" evolved into "rosmhvalr" and then "rosmar" in Old Norse, and eventually "walrus" in English.
